Summer officially expires on Sunday — but Tucson is still sweltering with highs at or near 100 degrees even as the first faint signs of fall color appear in the Catalina Mountains north of the city.

Tucsonans have sweated out 73 days of 100 degrees or higher so far this year, including nine this month. That’s already well over our normal of 62 days of triple-digit weather for the entire year in recent decades, said Ricardo Humphreys, a meteorologist with the National Weather Service.

And here’s the thing: We’re not necessarily out of the woods — or desert — when it comes to more 100-degree highs before the year is out. Tucson has topped out in triple digits as late in the year as Oct. 16. That happened in 1991, but it’s unusual. The city’s average last day of 100-degree weather is Sept. 18.

Forecasts for Friday and the weekend call for highs in the upper 90s, Humphreys said.

“But it’s still in the realm of possibility to hit 100” later this month or next month, he said.

Still, outdoor athletes, people who work outside during the heat of the day, and those of us who are just growing weary of triple-digit days can take heart in this: We’re virtually certain not to come even close to the record number of days of 100 degrees or higher in a single year. That withering record of 99 days was set in 1994.


If you are a member of the sick-of-summer set, you might be happy to hear that hints of autumn were showing up this week in the Catalina Mountains north of Tucson.

There, temperatures were topping out in the 70s and visitors were finding just a few aspen and maple trees showing the first tinges of autumn color.

“There’s one maple tree I watch along the (Catalina) highway in the Bear Wallow area, and it’s starting to get a little red,” said Pamela Selby-Harmon, officer in charge of the Mount Lemmon Post Office in the village of Summerhaven.

Elsewhere in the Catalinas, aspen leaves were turning gold on a few — but only a few — trees along trails and roads. Another sign of the coming season: Some ferns have faded from their emerald green of summer to the coppery-brown of autumn.

The best of the color show in the range usually develops in October.

“As long as we don’t get a big hailstorm or high winds, we see color for at least a month,” Selby-Harmon said. “It often peaks the second week of October, but doesn’t fully fade until later.

“We’re hopeful this year because we’ve had a nice amount of rain — 18.62 inches right here at the post office — and that makes for a beautiful fall season,” she said.

Contact reporter Doug Kreutz at or at 573-4192. On Twitter: @DouglasKreutz